rankscope
Beats most of the alternatives on the topic by a noticeable margin, and a look at rankscope did not change that at all, this is one of the better corners of the open internet for this kind of content and I am glad I clicked through rather than skipping past quickly like I usually do.
discoverinfiniteideas
Honest assessment is that this is one of the better short reads I have had this week, and a look at discoverinfiniteideas reinforced that, the bar for short content is low because most of it sacrifices substance for brevity but this site manages both at once which is harder than it sounds for most writers attempting it.